Magnetic field and temperature sensing with atomic-scale spin defects in silicon carbide

Abstract

Quantum systems can provide outstanding performance in various sensing applications, ranging from bioscience to nanotechnology. Atomic-scale defects in silicon carbide are very attractive in this respect because of the technological advantages of this material and favorable optical and radio frequency spectral ranges to control these defects. We identified several, separately addressable spin-3/2 centers in the same silicon carbide crystal, which are immune to nonaxial strain fluctuations. Some of them are characterized by nearly temperature independent axial crystal fields, making these centers very attractive for vector magnetometry. Contrarily, the zero-field splitting of another center exhibits a giant thermal shift of −1.1 MHz/K at room temperature, which can be used for thermometry applications. We also discuss a synchronized composite clock exploiting spin centers with different thermal response.

Engineering near-infrared single-photon emitters with optically active spins in ultrapure silicon carbide

“…This approach can be used to deterministically incorporate 36 these atomic-scale defects in electronic 21 and photonic structures 37 as well as in nanocrystals 38 . Together with their extremely narrow optical resonances (on the order of 0.01 nm at low temperature 16 ) and recently demonstrated optically detected spin resonances at ambient conditions 23 , our results open exciting opportunities for various quantum applications with spin-photon interface.…”

“…5). The ODMR maximum is observed at 71 MHz, corresponding well to the zerofield spin splitting of V Si (V2) in 4H-SiC in much dense V Si ensemble 23 . The experiment of Fig.…”

“…As has been mentioned in the introductory part, the generation of optically active spins is important for solid-state quantum ARTICLE computing and communications, sensing, precision measurement and so on [1][2][3][4][5]12,16,23 . Very recently, single emitters in the visible spectral range have been isolated in SiC wafers 20 and nanoparticles 35 .…”

“…In the ODMR experiment, the radio frequency radiation provided by a signal generator is amplified and guided to a thin copper wire terminated with a 50 Ohm impedance. We use a standard lock-in detection scheme, described elsewhere 23 .…”

Room-temperature near-infrared silicon carbide nanocrystalline emitters based on optically aligned spin defects

“…The optimum excitation wavelength of these defects is about 800 nm and they emit in the NIR spectral range 26 , fulfilling the property (ii) for optimal bioimaging. Remarkably, there is a family of V Si -related defects in SiC with room-temperature optical spin readout 28,29 , allowing for sensing magnetic 30 and electric 31 fields as well as temperature 30 . Our top-down approach is suitable for mass production of SiC NCs containing different types of atomic-scale defects.…”